Apparatus for gauging and determining special coordinates for a source of radiation to be employed in obtaining a radiograph of a patient are well known and have been in use for over 20 years. For example, a U.S. Pat. No. 4,630,375 of Spolyar discloses a template-like gauge having a plate-like body which is at least in most part transparent and carries a reference point and a first plurality of parallel lines along with a read-out portion. The read out portion is made up of second and third pluralities of lines to cooperatively define a plurality of gauge areas. Each of the gauge areas represents a different set of coordinates for aiming an associated X-ray source. An additional plurality of radiating angularly spaced gauge lines are also provided. When a plate-like body is placed against a lateral cephalogram and the reference point is situated at the articulare and the palatal plane of the cephalogram it is positioned at least parallel to one of the lines in the first plurality of parallel lines, the sella appears in one of the gauging areas and the coordinates corresponding thereto are employed for aiming the X-ray source.
A method and apparatus for generating cephalometric images is also well known. For example, a U.S. Pat. No. 5,278,756 of Lemchen et al. discloses a method and apparatus for generating a cephalometric tracing directly from a patient by directly generating digitized two or three dimensional data from the patient's head to define locations of preselected landmarks thereon from which diagnostic data points required for the cephalometric tracing are computer generated and connected so as to produce a cephalometric tracing. A video recording of the patient's head corresponding to the spatial orientation of the cephalometric tracing at the time of the generation of the data is made, reproduced in visible form to the same scale as the cephalometric tracing and superimposed on the tracing on a video monitor.
A further development in the method of cephalometric evaluation of dental radiographs is also disclosed in a U.S. Pat. No. 5,318,441 of Keller. As disclosed therein, a method for cephalometric evaluation includes steps of generating radiographic, X-ray or other images of a patient's individual orthodontic structure, positioning this image in alignment with a graphical depiction of a norm value orthodontic structure and comparing the individual's structure to the norm value structure to analyze development and to determine a course of orthodontic or other treatment.
Finally, a U.S. Pat. No. 5,342,202 of Deshayes discloses a method for modeling cranio-facial architecture. As disclosed, a process for modeling cranio-facial architecture on the basis of a lateral cephalometric X-ray by determining bony points and plotting analysis lines, measuring the angles and comparing them with thresholds and measuring the lengths and comparing the lengths with one another.
Notwithstanding the above, it is presently believed that there is a need and a potential market for an improved device and method for measuring the skeletodental relationship of a human skull directly from a cephalometric radiograph of the craniofacial structure in accordance with the present invention. There should be a demand for such devices because such devices are believed to facilitate the work of dental students, dentists, orthodontics, and researchers interested in studying dental malocclusions and monitoring the skeletodental relationships of the human craniofacial structures. Such devices should be in demand because they help in measuring the skeletodental relationship of the human skull to study and diagnose dental malocclusions and assess the treatment to be performed. Such devices and methods also help in comparing the changes in the skeletodental relationships after treatments and compare the skeletodental relationships between samples of patients and different populations. It is also presently believed that such devices can be produced at a relatively modest cost and greatly facilitate the work of dentists and orthodontists in evaluating and analyzing the treatments for patients with malocclusions.